The present invention relates to a semiconductor apparatus and a semiconductor package and, more particularly, to a technology which is successful for a semiconductor integrated circuit apparatus having a large calorification generated therein.
A semiconductor apparatus is such that a large number of devices, such as transistors, are formed by laminating a number of thin films on a semiconductor substrate, and electrodes used for leading out electrical signals therethrough are provided in the devices.
Since these devices generate the heat during the operation of the semiconductor apparatus, the temperature rises in each of the device formation regions so that there may be caused in some cases changes in the electrical characteristics and thereby a reduction of the reliability. In the prior art, a material having a high heat conductivity is employed as the material for sealing the semiconductor apparatus for preventing such undesired problems.
The main heat source of the semiconductor apparatus is a p-n junction portion very near the surface of the semiconductor substrate. Then, most of the heat generated in the p-n junction is transferred through the semiconductor apparatus body to reach up to the surface of the semiconductor apparatus. Thereafter, it is transferred through the package body tightly bonded to the semiconductor apparatus to be released towards the outside of the apparatus. However, in the semiconductor apparatus, the temperature rise in the device portions is not sufficiently controlled as the devices of high density are integrally formed on the semiconductor substrate.
Then, in order to solve the above problem, a heat releasing function is provided in the semiconductor apparatus itself. For example, there is made an attempt to diffuse the heat in a direction parallel with the semiconductor substrate through a metallic thin plate which is formed in the semiconductor apparatus in the form of layer by the plating or the like.
Incidentally, with respect to such a prior art, there is published JP-A-48-8467.
However, when the present inventors made an attempt to form the devices more densely in the semiconductor substrate it was found that the temperature rise in each of the device portions cannot be sufficiently controlled by the above prior art.
More specifically, since in the prior art semiconductor apparatus, thick insulating films are formed over the p-n junction or the wiring, the heat radiation from the surface of the semiconductor apparatus is restrained. Therefore, most of the heat generated in the apparatus is only released from the rear surface of the semiconductor apparatus through the inside of the semiconductor substrate.
Moreover, in the case where there is an unbalance in the arrangement of the devices in the semiconductor apparatus, the prior art semiconductor apparatus has a poor heat radiating performance, and, therefore, that apparatus is partially overheated. As a result the electrical characteristics of the device are partially varied.